Peel onion and garlic. Halve the onion and cut into slices. Press the garlic through. Fry the gyros in 1 tbsp. hot oil while turning for 5-6 minutes, remove.
Heat 1 tablespoon of oil in a pot. Brown the onion and garlic in it. Briefly sauté the tomato paste and flour. Tomatoes together with juice, 1⁄4 l water and broth stir in, bring to the boil. Chop the tomatoes slightly. Add salt, pepper, sugar and oregano spices.
Cover the soup and simmer for about 15 minutes.
Mash tomatoes lightly, add gyros, bring to the boil and simmer for about 5 minutes. Season soup to taste again. Serve with 1 blob of tzatziki. Garnish with oregano. Add the rest of the tzatziki. Goes well with baguette.